No obvious associations of HLA-tissue types with chronic Chagas' disease were found when over 400 individuals were typed at A, B, and C-loci. DR (B-cell) typing was similarly negative in about 300 total cases. Twelve isolates from patients with cutaneous leishmaniasis were tested in BALB/c mice via the footpad route to yield a spectrum of responses from no to large lesions. Number of vaible organisms that could be cultured from biopsied skin lesions were estimated before and after treatment in patients with disseminated cutaneous leishmaniasis from the Domican Republic. An ELISA test has been developed for antibodies in human stronglyoidiasis using larval antigen from S. stercoralis and S. ratti.